The present invention relates to a map data delivering system, a map data delivering method, and a communication terminal in relation to technologies for delivering and updating map data.
In a conventional car navigation system (hereinafter, referred to as a car navigation), in order to compensate for disadvantages such as difficulties of carrying it due to solid fixation to a car structure or of operating or using a display interface, a service has been realized for connecting from a personal computer located in a user's home to a dedicated website via the Internet, executing a destination search or route setup, and downloading the results to a car navigation. Particularly, a car navigation internally including a hard disk drive (HDD) can store a large amount of data, and thus, the aforementioned services can be readily realized.
In the aforementioned website, point of interest (POI) information is provided with much more latest information in comparison with internal information of a car navigation. In addition, when information is provided and shared between users of the website, detailed local information and destinations not included in a typical car navigation map can be obtained and set.
When such information is downloaded onto a car navigation, the POI information is established based on latitude and longitude information common to all devices. Therefore, the downloaded information is allowed to be used as a destination of traveling route search in a car navigation system.
On the other hand, the route information searched or shared from such a website can be input to a car navigation in the format of a set of latitude and longitude information. However, in some cases, the same route can be differently represented in a car navigation due to inconsistency of a map version or a detailed view. For example, while a bypass road is opened to traffic according to a map on the website, the map of the car navigation may not appropriately reflect the bypass road if it has an old version.
In order to address such a problem, when the map of a car navigation does not have road network information corresponding to the route information, a method of supplementing the lost road network information based on the route information has been proposed. For example, when the map of a car navigation is shown in FIG. 17A, the road network information passing through areas 4, 5, and 6 is needed, road network information represented by a dotted line of FIG. 17B is added to the format of a conventional road network as supplement map information. As a result, any route representation can be displayed, and a route search or a route guide can be implemented using a conventional algorithm.
In addition, a latest version of the map information of a car navigation is distributed on a regular basis, and a user can obtain the latest version of the map and update any version of the map. For example, in a patent document JP-A-2006-317643, a method of downloading the latest version of the map in plural methods and updating the map is disclosed.